CDK Platform: Platform should have classification for browsers used on MacOS

#### Feature Description

Platform should classify MacOS based browsers. The current feature lacks MacOs detection. Additional flag required MACOS:true

#### Use Case

Open Angular App on macOS Chrome or Safari. The following output log is for Platform on MacOS chrome

ANDROID: false
BLINK: true
EDGE: false
FIREFOX: false
IOS: false
SAFARI: false
TRIDENT: false
WEBKIT: false
isBrowser: true

#### Expected Feature:

ANDROID: false
BLINK: true
EDGE: false
FIREFOX: false
IOS: false
**MACOS:true**
SAFARI: false
TRIDENT: false
WEBKIT: false
isBrowser: true

Start from the CDK Platform browser-classification code and review how the existing platform flags are determined. Compare the current MacOS Chrome and Safari output with the expected output in this issue; done means the platform reports MACOS as true for MacOS-based browsers without changing the other flags.

Written by the indexing model from the issue text.